Pregnant women should drink no more than four cups of coffee a day, a government agency has advised.

Those exceeding this limit may risk low birthweight babies - or even miscarriage.

The advice comes from the Food Standards Agency (FSA).

It puts a figure on the previous Department of Health recommendation of "moderate" consumption.

The FSA's Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (CoT) looked at how caffeine affected pregnancy.

This doesn't mean cutting out coffee completely but is about taking a sensible precaution and not having more than the
equivalent of four cups of coffee a day.

Suzi Leather, FSA

It found drinking more than 300mg - or four average sized cups of instant coffee per day - could be linked to low birthweight and possibly miscarriage.

Daily limits

Caffeine is naturally found in coffee, tea and chocolate. It is also added to some soft drinks and "energy" drinks.

The 300 mg daily limit roughly equals:

4 average cups or 3 average size mugs of instant coffee

3 average cups of brewed coffee

6 average cups of tea

8 cans of regular cola drinks

4 cans of "energy" drinks

400 grams (8 standard 50 g bars) of normal chocolate

The FSA set out caffeine intakes for individual items, so pregnant women can "mix-and-match", within their quota.

They are:

Average cup of instant coffee - 75 mg

Average mug of coffee - 100 mg

Average cup of brewed coffee - 100 mg

Average cup of tea - 50 mg

Regular cola drink - up to 40 mg

Regular energy drink - up to 80 mg

Normal bar of chocolate - up to 50 mg

Caffeine can also be found in certain cold and flu remedies.

Practical advice

Suzi Leather, deputy chair of the FSA, said: "This doesn't mean cutting out coffee completely but is about taking a sensible precaution and not having more than the
equivalent of four cups of coffee a day.

"Of course it's easy to forget that its not just coffee that contains caffeine, but tea, soft drinks and chocolate too.

"Because of this we have tried to set out our advice in a way that is practical and easy to understand."

The FSA said pregnant women should always seek advice from their doctor or other health professionals on the appropriate diet during pregnancy.

A spokesman for the industry-backed Coffee Science Information Centre said: "This is good news for coffee drinkers because it endorses that coffee drinking in moderation - four to five cups a day - is perfectly safe during pregnancy."